Antisense inhibition of methylenetetrahydrofolate reductase reduces survival of methionine-dependent tumour lines.
Br J Cancer
; 87(2): 225-30, 2002 Jul 15.
Article
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| MEDLINE
| ID: mdl-12107847
ABSTRACT
Transformed cells have been documented to be methionine-dependent, suggesting that inhibition of methionine synthesis might be useful for cancer therapy. Methylenetetrahydrofolate reductase synthesises 5-methyltetrahydrofolate, the methyl donor utilised in methionine synthesis from homocysteine by vitamin B(12)-dependent methionine synthase. We hypothesised that methylenetetrahydrofolate reductase inhibition would affect cell viability through decreased methionine synthesis. Using medium lacking methionine, but containing homocysteine and vitamin B(12) (M-H+), we found that nontransformed human fibroblasts could maintain growth. In contrast, four transformed cell lines (one colon carcinoma, two neuroblastoma and one breast carcinoma) increased proliferation only slightly in the M-H+ medium. To downregulate methylenetetrahydrofolate reductase expression, two phosphorothioate antisense oligonucleotides, EX5 and 677T, were used to target methylenetetrahydrofolate reductase in the colon carcinoma line SW620; 400 nM of each antisense oligonucleotide decreased cell survival by approximately 80% (P<0.01) and 70% (P<0.0001), respectively, compared to cell survival after the respective control mismatched oligonucleotide. Western blotting and enzyme assays confirmed that methylenetetrahydrofolate reductase expression was decreased. Two neuroblastoma and two breast carcinoma lines also demonstrated decreased survival following EX5 treatment whereas nontransformed human fibroblasts were not affected. This study suggests that methylenetetrahydrofolate reductase may be required for tumour cell survival and that methylenetetrahydrofolate reductase inhibition should be considered for anti-tumour therapy.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Tionucleótidos
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Oligodesoxirribonucleótidos Antisentido
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Inhibidores Enzimáticos
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Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH
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Metionina
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Proteínas de Neoplasias
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Antineoplásicos
Límite:
Female
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Humans
Idioma:
En
Revista:
Br J Cancer
Año:
2002
Tipo del documento:
Article
País de afiliación:
Canadá